Elements of a generalized duration forecasting model of test-and-fix cycles

Rework is integral to product development. The dynamism, circularity and concurrency properties of rework cycles inhibit attempts to estimate the duration and resources required of development phases. This difficulty is especially evident in testing of software-intensive systems. Dynamic modeling of test-and-fix cycles has addressed this problem and provided good forecasting of test phase durations, but has also produced good results in supporting resource allocation and process improvement decisions. A different model was produced for each of six projects. Though models of test-and-fix processes can be very detailed, a basic model of common elements has been identified through an analysis of commonality and variation in the six project models. The analysis has been used to specify a generalized test-and-fix model.